At school entry, many children encounter difficulties because of social, emotional, and behavioral problems, which can co-occur with, and be complicated by, unhealthy lifestyle behaviors such as low physical activity, excessive screen time, and inadequate sleep. Despite the fact that both domains are critical to child development, most of the research on preventive interventions with young children has focused on either one domain or the other, but seldom both. There is a clear need for family-based interventions that integrate the two domains because parents exert major influence on both social-emotional-behavioral functioning and healthy lifestyle. With preschool-age children, addressing parenting and family environment represents one of the stronger modes of intervention. Utilizing referrals from community-based organizations serving economically disadvantaged as well as high-risk families, this study addresses both health and behavioral domains through a family-based intervention. The home-delivered prevention intervention includes content on strengthening positive behaviors in children, managing misbehavior, and addressing healthy lifestyle choices. Families engage in practical skill building (e.g., behavioral teaching; planned activities training) and have the opportunity to practice these skills and receive feedback. The study involves a preliminary evaluation of the feasibility and initial viability of an integrated intervention, as well as the collection of information on other essential components regarding the delivery of the intervention. The sample includes high-risk families who have at least one preschool-age child and who have been referred for services through a community-based agency. The design involves randomization of 60 families to either the home-delivered integrated intervention or a wait-list control. The preliminary study: 1) evaluates the feasibility and acceptability (e.g., participant recruitment, retention during intervention, and dosage/participation) of an integrated intervention with families in an elevated-risk sample; 2) examines changes in child (e.g., behavioral problems, physical activity, sleep) and parent (e.g., stress, parental confidence) outcomes as a function of intervention; and 3) evaluates the assessment protocol with respect to acceptability and barriers encountered by participants. This study is significant because it intervenes with young children to promote positive outcomes as children enter school. The study is innovative in addressing concurrently the two domains of social-emotional-behavioral functioning and healthy lifestyle behaviors in 3- to 4-year-old children through a home-delivered family-based intervention. Intervention for families of preschoolers addressing the prevention of child behavior problems and the promotion of healthy lifestyles will create the best outcomes for young children as they enter Kindergarten. Results of this study will inform decisions about the design of a well-powered R01 prevention clinical trial.